Transfer case grind EDIT: front axle grind

My transfer case grinds pretty bad when engaging 4H in cold weather. It engages fast, just grinds while doing it. It’s filled with amsoil 75w90. It happens even if I go slow and am coasting. Is this a problem or normal? Oh also I’m an automatic

 

It's normal to hear it click or clunk. Grinding is not normal.

 

What do you think is wrong? Are the synchronizers going bad? I have no idea how these transfer cases mesh the gears

 

I only get a clunk if I engage/disengage while accelerating or decelerating. If I'm going at a slow steady crawl it simply clicks.

 

I get the clunk under those conditions too..or I used to. Now I mostly get a grinding when engaging but just a clunk when disengaging. Me going slow is like 20-30 mph but IIRC even going like 10 mph it still grinds

 

It is chain driven. It's identical to shifting gears on a bicycle. It sounds like there may be damage to the gears and/ or the chain is stretched. This is kind of worst case scenario... I can't think of what else would make it grind.

When you changed the gear oil, was there much metal in it?

Edit: not at all like shifting a bike. The video in post 27 explains it. I learned something new. Good stuff!

 

Grind is not normal.

 

Change oil spring of 2017, the oil in it looked perfectly fine but just wanted to get good fresh oil in it.when I changed the oil metal didn’t come out but I didn’t drive it around to stir things up before draining it. This all started last spring when it got real cold and it started grinding. Then spring/summer rolled around and it started engaging very smooth and very quick. Now where in a cold spell again and it’s grinding.

 

Are you shifting into 4x4 with the real wheels slipping at all?

 

Not that I can tell, it is on a snowy road but I try my best to shift while coasting so there’s no energy in the drive train

 

That's good. I'm just trying to think of what would make the chain slip.

And you say it doesn't grind in warmer weather?

 

It shouldn't be the oil, but in the spirit of KISS. I would change the oil. I suggest Redline MT 90. $13 and five minutes of your time may make all the difference.

 

^+1
MT 90 has done some magic for me before.

 

Nope as of the previous summer is does not grind in warm weather, it’s supposed to get around 50 in the next few days and I’ll piss around with it and see if it grinds. Do you think the GL5 rating on the amsoil is “too slippery” for the transfer case like it is for our manual trannies?

 

Also I just realized that my front tires are significantly worn compared to my rear tires. This means my front tires are spinning faster than my rear which would act like I was trying to engage 4wd with tires slipping? Another thing, I don’t think I notice it grinding in the summer because I only use 4wd while on a farm near me and I go real slow when driving around there

 

If your front tires are worn down a lot in comparison to your rear tires , you will get a grind .
The synchronizer hub inside the transfer case has the job of matching the front driveshaft rotating speed with the rear driveshaft rotating speed as you select 4x4 high .
If your front tires are wore out , the front driveshaft will be turning faster than the rear driveshaft .
a suggestion would be to come to a complete stop before selecting 4x4 which should eliminate the grinding until you replace the front tires
https://www.tacomaworld.com/threads/transfer-case-transfer-cases-in-first-and-2nd-gen-trucks.345652/

 

I don't know exactly how the t-case shifts, but I do know that it is nothing like how a bicycle shifts.

 

Was just going to ask about tires. If tires are off a 1/8 inch difference between front n back it puts alot of binding in the system. THATS y i rotate my tires every oil change. Seen too many destroyed tcases from tires.

 

You are correct . I beleive this is why Toyota says to rotate every 5k
The chain in the transfer case is direct drive ... it will not be causing the grinding .
Chains will make noise as they stretch because they will slap the inside of the transfer case housing .but they will never grind between 2 high to 4 high

 

I do rotate my tires every oil change but I had an out of balance rim that wore down a pair of tires really quickly so I just replaced two of them. So now the question is, did I do any damage to the case by doing this? Do you think I should drain the oil and put fresh stuff in incase there’s metal floating around?